Room front construction for sand blasting apparatus



1936- w. A. ROSENBERGER 2,063,054

ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS Filed May 2, 1934 6 Sheets-Sheet l Dcc. 8, 1936. w. A. ROSENBERGER ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS 6 Sheets-Sheet 3 Filed May 2, 1934 1936- w. A. ROSENBERGER 2,063,054

ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS Filed May 2, 1934 6 Sheets-Sheet 4 [In-H H WHLMHLHWHWH Dec. 8, 1936. w. A. ROSENBERGER ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS 1934 6 Sheets-Sheet 5 Filed May 2 Wi/l/am A. R06 enbe/yer JW +Wm 1936- w. A. ROSENBERGER I 2,063,054

ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS Filed May 2, 1934 6 Sheets-Sheet 6 Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE ROOM FRONT CONSTRUCTION FOR SAND BLASTING APPARATUS Application May 2, 1934, Serial No. 723,552

13 Claims.

This invention relates generally to sand blasting equipment. More particularly it has to do with room front constructions for rooms in which sand blasting operations are carried out.

Constructions have been heretofore proposed wherein a room is provided with a front having a vertically movable curtain, the latter having apertures therein through which the work may be observed by the workman standing on the outside of the room. The curtain in such prior constructions has also been provided with a plurality of slits, through which the nozzle may be progressively inserted as the Work proceeds.

' Although the above mentioned room constructions represent a great improvement over the old practice of having the Workman carry out the blasting operation in the same room with the work, they nevertheless possess several disadvantages. One of the major disadvantages of such prior constructions resides in the fact that they are so constructed that the workman is unable to closely follow, or properly inspect, the work, with the result that material is often spoiled. It is moreover necessary, in such constructions, for the worker to support the nozzle and move it over the face of the work as the work progresses, which, especially when coupled with the fact that the worker is able to direct the blast at various angles with the surface of the object being out, often results in inferior work. Such prior constructions are also inefficient as regards their dust retaining ability with the result that dust gets into the atmosphere and endangers the health of the workmen.

It is accordingly a primary object of my invention to devise a novel blasting-room front construction that gives the workman a clear view of the work at all times and which may be readily operated to allow inspection of the work.

It is a further major object of my invention to devise a novel blasting-room front construction that will very efliciently prevent dust from escaping from the room where the operation is being carried out, and yet which will permit ready movement of the nozzle over the surface of the work.

It is another important object of the present invention to so construct a room front, having a Window therein and a nozzle associated there with, that the window may be opened without moving or disturbing the nozzle.

Another object of this invention resides in the provision of a blasting-room front with a window which is mounted for rocking movement about a horizontal axis, to thereby provide ready access to the work.

Another object of my invention is to provide a blasting-room front with means for supporting an abrasive nozzle.

It is a further object of the invention to provide a blasting-room front of the character having an opening through which a nozzle may be inserted, with means for supporting a nozzle for guided movement upon the room front so that it will project through the opening and may be moved to various regions of the opening to follow work located in the room.

It is another object of my invention to provide an apertured sand blast room front, through which a nozzle is adapted to project, with means that will prevent sand from escaping from the room by way of the aperture, and yet will not interfere with movements of the nozzle into various regions of the aperture.

My invention further aims to devise an apertured blasting-room front of the character having a nozzle manipulating opening provided in a vertical Wall thereof, and having means for guiding a nozzle for defined movement into various regions of the opening, and to associate sand bafiiing means therewith which, disposed in the path of movement of the nozzle, is freely displaceable by engagement of the nozzle therewith as it undergoes movement.

It is another object of my invention to devise a supporting mechanism for a sand blast nozzle which is adapted to be moved over the face of the work and maintains the nozzle in a definite angular position with the surface at all times.

It is a further object to so design a sand blasting-room front construction having an inspection window and sand bafliing members that the window is operable to lift the sand baffling members out of the way and afford full visual inspection of the work when the window is opened.

My invention further aims to devise a supporting mechanism for a sand blasting nozzle that will permit the nozzle to undergo circular motions over the surface of the work but will maintain it in a definite predetermined angle with respect thereto.

It is another object of my invention to provide a sand blasting apparatus of the character having a nozzle mounted for horizontal movement within an opening in a room front, or the like, with a plurality of sets of sand baffling members located in the path of movement of the nozzle, one of the sets terminating adjacent the path of nozzle travel.

My invention also aims to provide sand blasting equipment of the character having .a vertically movable frame member, with a transversely movable sand blasting nozzle.

It is another object of this invention to improve the curtain supporting mechanism of sand blast apparatus having a vertically movable curtain, and it is also an object to devise a novel illuminating organization for apparatus of this character.

Further objects of my invention will become apparent as the detailed description thereof proceeds in connection with the annexed'drawings, and from the appended claims.

In the drawings,

Figure 1 is a perspective view of my novel room front construction with the sand blast nozzle in operative position and itillustrates the inspection window disposed in fully open position, thereby affording visual inspection of the work.

Figure 2 is a fragmental sectional view of the curtain guide structure and it is taken on the line 2-2 of Figure 1.

Figure 3 is a view similar to Figure 2, but it is taken on line 3-3 of Figure 1.

Figure 4 is a perspective View illustrating the rear of the room front construction shown in Figure 1 as it appears when detached from the room.

Figure 5 is a view similar to Figure 1, but it illustrates the window disposed in closed or working position.

Figure 6 is a sectional view taken on the line 6-6 of Figure 4.

Figure 7 is a sectional view taken on the line 1'! of Figure 4.

Figure 7A is a sectional view of the counterweight assembly shown in Figure. 1.

Figure 8 is an enlarged fragmental elevational view of the frame structure which supports the window, the latter being removed therefrom in this view for sake of clarity.

Figure 9 is a sectional View taken substantially on the line 99 of Figure 8, looking in the direction of the arrows.

Figure 10 is an isometric view of a portion of the window supporting frame structure.

Figure 11 is an enlarged elevational view of the window shown in Figure 1, and it is illustrated as. being removed from its supporting frame structure.

Figure 12 is a sectional view taken substantially on line I2I2 of Figure 11, illustrating the parts as they appear when viewed in the direction of the arrows.

Figure 13 is a perspective view of the nozzle supporting carriage of the device shown in Figure 1, and it illustrates the nozzle in position thereon and the nozzle guide plates disposed in their separated position.

Figure 14 is a view similar to Figure 13, but it shows the nozzle guide plates as being disposed in their closed position and it also illustrates the manner in which the nozzle and carriage are grasped for manipulating them tocarry out the blasting operation.

(Figure 15 is a side elevational view of the nozzle supporting carriage shown in Figures 13 and 14, and parts thereof have been shown in section for the purpose of more clearly illustrating the structure involved.

Figure 16 is an enlarged sectional view taken on line IB-IG of Figure 15, looking in the direction of the arrows.

Figure 17 is a sectional view of a modified form of room front construction also forming part of my invention.

Figure 18 is .a fragmental sectional view of the construction shown in Figure 1'7 and it illustrates the inspection window as being disposed in partially open position.

Figure 19 is a view similar to Figure 18, but it illustrates the inspection window as being disposed in fully open position, and

Figure 20 is an enlarged sectional view of the curtain shown in Figure 17, and it illustrates the manner in which the stifiening members are secured thereto.

With continued reference to the drawings, wherein like reference characters are employed to designate like parts, through the several views thereof, my novel sand blasting room front construction consists of a frame structure designated generally as A, a movable frame member B, which is supported for vertical movement on a curtain which carries an inspection window C and a sand blasting nozzle supporting carriage B. The frame construction will now be described.

The frame is constructed of a pair of vertical members I I, which are generally channel shaped and are rigidly joined by horizontal plate members I2 and I3. With particular reference to Figures 1 and '7, plate I3 is provided with a forwardly extending flange I4. Secured to flange I4, by means of bolt and nut assemblies I5, is a horizontally extending plate I6. The ends of plate IB are secured to angle pieces I! which are riveted or otherwise secured to the upper ends of channel members II. An angle member I8 is secured to the rear edge of plate I6 by means of bolt or nut assemblies I9 for the purpose of stiffening it, and preventing it from flexing in service.

Secured to the lower edge of plate I3, by means of bolt and nut assemblies 2| and a binding strip 22 is a flap 23, which is preferabl constructed of a piece of rubber-impregnated fabric. Flap 23 is adapted to cooperate with the curtain and function as a baffle for minimizing the escape of abrasive or dust laden air from the upper part of the room in a manner that will be pointed out hereinafter.

With particular reference to Figures 4 and 6, the upper edge. of plate I2 is provided with an inclined flange 28. and connected thereto by means of bolt and nut assemblies 29 and a binding strip 3| is a flap member 32, which is similar to flap 23 and is adapted to cooperate with the curtain and minimize the escape of abrasive material from the lower part of the room in a manner that will be hereinafter described.

The frame construction just described is adapted to be secured to the floor of the building in which the apparatus is used by any desired form of securing means which may be associated with a forwardly extending flange 33 formed on plate I2, and with a pair of angle pieces 34 connected to channel members II.

The curtain structure is adapted to be guided for vertical movement by means of guides provided on the front of the frame structure just described, and the construction of the right hand guide shown in Figure 1 will now be described.

Referring more particularly to Figure 2, a metal strip 35 and a guide plate 36 are secured to the front flange of member I I by means of bolt and nut assemblies 31, Strip 35 functions as a spacer member, and as seen in Figure 2, it spaces guide plate 36 sufiiciently from flange member II to provide a channel or guideway therebetween. The left hand guide construction is shown in Figure 3 and is somewhat similar to that just described, except that an angle member 38 is also secured to the face of guide plate 38 by means of bolt and nut assemblies 31. The forwardly extending flange 39 of member 38 forms a guide for the counterweights that will be hereinafter described.

Secured to the upper end of guide 36 is an angle piece 4!, and a similar angle piece 42 is secured to the lower end of member 38. Angle pieces 4| and 42 are adapted to function as upper and lower window-frame stops respectively in a manner that will be hereinafter pointed out.

The frame construction just described is adapted to be secured in any suitable form of sand blasting room structure by means of suitable fastening means extending through apertures 43 formed in the rear flanges of members II. The room construction may take any desired form, and as it forms no part of the present invention it has not been disclosed. It, however, preferably takes the form of an enclosure having a door located in a side thereof so that the piece of work that is to be operated upon may be introduced therein on a truck or the like, or it may be provided with an opening in the ceiling to allow the work to be handled by a crane or the like. An exhaust fan is also preferably associated with the room for removing the dust laden air therefrom. The present room front construction is adapted to be employed with a room having a door in the side thereof, and to this end a door latch keeper 44 is secured to right hand member II for cooperating with the door of the room.

As previously indicated, frame B is adapted to be supported by a vertically movable curtain, and although the curtain may take any suitable form, I preferably employ a two-part, roller supported curtain that will now be described.

With reference to Figure 1, a pair of brackets 45 are secured to members l as by means of bolt and nut assemblies, and a roller 46, having a flange 4! provided on the left hand end thereof is journaled in brackets 45 in any suitable manner. If desired, anti-friction bearings of any suitable construction may be associated with brackets 45 and roller 46 so that the latter may operate with a minimum of friction. A curtain 48 is attached to roller 46 in any suitable manner and extends downwardly in the guides and is connected to frame B in a manner that will be described hereinafter.

A pair of brackets 49 are secured to the lower ends of members II and an idler roller 5|, and a curtain carrying roller 52 are journaled therein. Roller 52 is provided on its left hand end with a flange 53 which cooperates with the curtain counter-balancing mechanism. A curtain 54 is secured to roller 52 and extends under idler roller 5| and upwardly between the guides defined by guide plates 35 and is connected to frame B as will be hereinafter described.

Although I have disclosed rollers 46 and 52 as being disposed in front of the construction, or exmriorly of the room, it is to be understood that either or both of them may be located within the room and a satisfactorily operating mechanism obtained. Moreover, curtain 54 may be wound on roller 52 in a direction opposite that disclosed and idler roller 5| dispensed with, but I prefer ably employ the construction disclosed as it insures freeing substantially all of the sand from curtain 54 before it is wound upon roller 52 in a manner that will be described hereinafter.

Frame B is accordingly mounted for synchronous movement with curtains 48 and 54 and I preferably provide the device with mechanism for counterbalancing the weight of frame B and its associated parts, and for also insuring that the curtain will be wound up on one roller as it is unwound from the other, and the mechanism that I preferably employ for attaining this result will now be described.

A cord 55 of any suitable character is connected to roller 46 and supports a counter-weight carrying member 56 at its lower end. A plurality of counter weights 5? are carried by member 56 and are provided on their rear faces with recesses which embrace flange 39, and are adapted to be guided for vertical movement thereby. Member 55, Figure 7A, is preferably hollow and a spring 58 is disposed therein, and is connected thereto by means of a bolt 53'. Connected to the lower end of spring 58, is a threaded member 59, to which a hook member 68 is adjustably connected by means of a nut assembly 5|. A cord 62 is connected to roller 52 and is secured to the lower portion of member 33. Cords 55 and 62 are wound upon rollers 46 and 52 in the proper direction to produce proper rotation thereof, as shown in Figure 1.

The mass of counter-weights 51 is preferably calculated to approximately equal the mass of frame B and its associated parts and also the unwound portions of curtains 48 and 54, in order to insure smooth operation with a minimum of effort on the part of the operator. Spring 58 is preferably interposed between cords 55 and 62 in order that the latter may be maintained taut at all times despite the changing effective radii of rollers 46 and 52 as curtains 48 and 54 are wound upon and unwound therefrom.

As previously stated, frame B carries the nozzle supporting carriage and the inspection window and the construction of frame B will now be de scribed. With reference to the Figures 1, 8, 9 and 10, an angle member 53 is secured to curtain 48 by means of bolt and nut assemblies 64 and a binding strip 65. Member 63 is provided with a horizontal portion 65 and a vertical portion 61, which, as seen in Figure 8, terminates short of the s des of curtain 48. strip 65, and the vertical portion of member 63 to which the binding strip is secured define guide members which are adapted to ride in the frame guides. Flanges 58. of a pair of vertical angle members 69, are secured to member 63 at '18 as by z means of butt welds or the like. Front flanges H of members 69 lie in the plane of, and are secured to, the front vertical portions of member 53 by means of welds l2. Flanges 88 of members 69 are provided with aligned apertures 14, which are adapted to pivotally support the inspection window structure that will be hereinafter described. Aligned with apertures 74 are a pair of bearing members l5, which are secured to flanges 58 of members 69 by means of welds 16.

The bottom of frame B is preferably defined by a channel member 78, having upper and lower carriage supporting and guiding flanges 19 and 8| respectively. The mid portion of member 18 is preferably disposed in the plane of flanges ll of members 39 and is secured thereto at either end at 82, by means of welds. A plate 83, which is also preferably disposed in the plane of portion ll of member 69, is preferably secured to member i8 by means of welds 84 and 85, and is secured The other ends of binding to the lower ends of members 69 by means of welds 86.

Member 18 is reinforced against twisting with respect to the frame by means of a pair of plates 81 which are secured thereto by means of welds 0i Plates 81 are secured to flanges 68 of members 69 by means of welds 89. A plate 9|, preferably disposed in the plane of flanges 19 and 8| of member 18, is preferably secured to the latter by means of welds 92. Plate 9I cooperates with member 18 so as to constitute a tubular section, thereby greatly increasing its resistance to flexing or twisting under the loads imposed upon it during operation.

A pair of dogs 84 are pivotally connected to portions 68 of members 69 by means of pins 95, and are adapted to restrain the nozzle supporting carriage from inadvertent removal from the device in a manner that will appear hereinafter. Curtain 54 is secured to member 83 by means of a bolt and nut assembly 96 and a binding strip 91.

Frame B is accordingly mounted for vertical movement in the guides defined by the front flanges of members I! and guide plates 36, the frame being guided at its upper end by the extrerm'ty of clamping strip 65 and the end of the vertical flange of member 63, and is guided at its lower end by the ends of clamping strip 81 and member 83. The parts just described fit fairly closely in order to prevent frame B from undergoing tilting movements when it is raised and lowered, so that the nozzle carried thereby will be maintained at a definite angle with respect to the work. Movement of frame B is preferably limited as it is raised and lowered by means of a lug member 100, which is secured to flange 10 of member 69, and is adapted to cooperate with angle pieces M and 42. Although I have illustrated curtains 48 and 54 and frame B as being mounted for movement in common guides, and I prefer to employ this structure, they may, if desired, be mounted in individual guides without departing from the spirit of my invention.

Nozzle carriage D is mounted for horizontal movement on member 18, and, although it may assume any desired configuration, it is preferably constructed of a flat metal plate IOI. Plate IOI is supported on flange 19 by means of a pair of wheels 502, and it is restrained against tilting and upward movements with respect thereto by means of a lower wheel I02 which cooperates with flange 8! of member 18.

Wheels I02 are identical in structure and, as they are secured to plate IOI in a similar manner, similar reference characters have been applied to the parts thereof and only one of them will be described. \Nheels I02 are flanged as seen in Figure 15 and they are rotatably journaled on shouldered bolts I03. Upper bolts I03, extend through apertures in plate I0! and are secured thereto by means of nuts 104, while lower bolt I03 extends through a vertical slot I05 located in plate IIJI. Wheels I02 are centered on bolts I03 by means of bushings I06 and I01. The enlarged portions of bolts I03 are so designed that, when nuts I04 are turned home, wheels 102 and bushings I05 and I01 will have sufficient play for proper operation. It is apparent that, by loosening nut Hi4 associated with the lower wheel, the entire lower wheel assembly may be moved vertically in slot N35 to increase or decrease the clearance between the wheel assemblies and member 18.

Upper wheels I02 are preferably enclosed in metal housings Hi8 which are provided with ears I09. Housings I08 are adapted to be drawn up into surface engagement with the rear face of plate IN by means of bolts H2 and nuts III. Housings I08 function to prevent sand from getting at upper wheel assemblies I02, thereby insuring proper operation thereof.

Plate I 0| is accordingly mounted for horizontal movement on rail member 18 and it may be, if desired, removed therefrom by lifting dogs 94 and moving the carriage away from rail 18. With reference to Figures 13 and 14, a handle I I3 is secured to plate NH and is adapted to be grasped by the operator for shifting the carriage. In Figure 15, a modified form of handle II3a is disclosed which extends rearwardly and is secured to the rear face of plate IOI by a welding operation.

Plate IOI is provided with a preferably circular aperture I I6, through which the sand blast nozzle is adapted to be inserted.

The nozzle supporting mechanism will now be set forth. A pin member II1 extends through an aperture in plate ml and is secured thereto by a weld II8 on the rear face of plate IN. A

lever I I9, having an elongated hub portion I20,

is journalled on pin H1 and is secured'against endwise removal therefrom by means of a cotter pin I2I or the like. A torsion spring I22 is mounted on hub I20 and its front end is provided with a hook portion I23 which is adapted to be looped under lever H9. The other end of spring I22 is provided with a hook portion I24 which is adapted to be selectively engaged with one of a plurality of apertures I25 located in plate IOI. A plurality of apertures I25 are provided so that the tension of spring I22 may be adjustably varied by inserting portion I24 thereof into the proper aperture in plate IOI.

A nozzle supporting member i 26, having a nozzle receiving aperture in its upper end and a clevis at its lower end, is pivotally connected to lever H9 by means of a pin I21. A nozzle assembly, designated generally as I28, has a supply pipe I29 connected thereto and extends through and is adapted to be secured in the upper end of I link I26 by means of a pair of set screws I32 or the like. The nozzle assembly proper consists of a nozzle pipe, a nozzle connector and a nozzle, but, as it forms no part of the present invention, and, as any type of nozzle construction may be used with my nozzle supporting construction, it will be referred to generally hereinafter as nozzle #28 and it will not be further described.

Nozzle I28 extends through aperture H6 in plate ml and is normally urged upwardly by spring I22, which is preferably adjusted to counterbalance the weight of the nozzle assembly and the portion of pipe or hose I29 that is normally supported above the floor, so as to insure vertical movements of the nozzle with a minimum of effort.

With the parts adjusted as seen in Figure 13, nozzle I28 may be moved over a circular area defined by the area of aperture I I6, and be directed against the work designated as E (Figure 1) and which, in the present instance, is a tombstone or I28, it is transmitted to the carriage, to frame B, and thence to curtains 48 and 54, with the result that the frame is lifted vertically, and curtain 48 is wound up on roller 46 and curtain 54 is unwound from roller 52. If it is desired tomove the assembly downwardly over the work, downward forces are applied to the nozzle and handle II3 so as to cause frame B to move bodily down- Wardly.

It is sometimes desirable to limit the nozzle to solely vertical movement or to movement over a comparatively narrow vertical area and I have accordingly provided plate I OI with a pair of guide plates I 33, which are mounted on plate I M for adjustment toward and away from each other and they are adapted to cooperate with the sides of nozzle I28 in a manner that will be hereinafter described. Plates I33 are secured to plate Illl by means of adjustable bolt and nut assemblies, and as they are identical in character, only one of them will be described. Referring more particularly to Figure 16, a pair of vertically spaced slots I35 are formed in plates IOI and extending therethrough are a pair of screws or bolts I35. Rectangular lug members I36 are received in recesses I31 formed in screws I35 and are welded or otherwise secured thereto. Lugs I36 cooperate with the side walls of slots I34 and prevent rotation of screws I35 in response to adjustive manipulation of nuts I38, which are threaded thereon.

\Vhen it is desired to guide nozzle I28 for vertical movements, nuts I38 are loosened and plates I33 are brought into the relation shown in Figure 14, in close proximity to nozzle I28. Nuts I38 are then tightened and the device is ready for operation. As seen in this figure, handle H3 is preferably grasped by the left hand and the nozzle grasped by the right. The operator is thereby able to produce vertical movement of the nozzle with his right hand, and when the particular vertical area of the work has been completed he is able with his left hand to move the carriage a sufficient distance to the right or left to bring a new area into cooperating relationship with the nozzle.

I preferably associate illuminating means with my improved construction, which, in the present instance, takes the form of an electric lamp bank, and in order to insure that the illumination remains of constant value at all times, I preferably mount the lamp bank on frame B, so that it may move up and down with the latter, and accordingly follow the nozzle over the face of the work.

With reference to Figure 4, a plurality of brackets I4I, supporting a plurality of lamps I42, are secured to horizontal flange 66 of frame member 63. Lamps I 42 may be of any desired construction and they are supplied with electricity by means of a conductor I43 which extends through a conduit I 44 and is connected to each lamp in any well known manner. Conductor I43 hangs in a loop from the end of the conduit, and extends through an aperture in frame member II. The loop is provided so that frame B and the lamp assembly may undergo vertical movement without interference from conductor I43. Conductor I 43 extends outwardly of frame member II and is associated with a switch I45 and a lead-in conductor I46, the latter being adapted to be connected to any suitable source of electric power (not shown).

The opening provided in frame structure B is provided with 2. preferably pivoted inspection window having a transparent portion through which the work maybe observed and also a portion having sand deflectingbaflies which permit ready operative vertical and horizontal movements of the nozzle and yet efficiently prevent abrasive material from escaping from the room. In this form of my invention, this window preferably takes the form of a window structure mounted for pivotal movement upon a. horizontal axis, and it will now be described.

With particular reference to Figures 11 and 12 of the drawings, a pair of horizontally extending angle members I39 and II aresecured, as by welding or the like, to a pair of end plates I52, thereby defining a generally rectangular frame. Secured to member I49 in any desired manner is an angle member I53. Secured to the depending flange of member I5 I by means of a bolt and nut assembly I54 and a binding strip I55, is a screen I56 which is preferably of relatively fine mesh. The lower edge of screen I56 is secured to member I53 by means of a pair of clamping strips I51, a bolt and nut assembly I58 and a plurality of washers I59. Washers I59 are disposed between member I53 and the clamping strip assembly in order to space the lower edge of the screen from member I53. Accordingly any sand or other abrasive that might find its way through screen I56 will drop and rest upon member I53 and can accordingly find its way out beneath the binding strip assembly and will not build up betweenthe screen and the glass. The ends of screen I56 are held in place by binding strips in a similar fashion.

Preferably a plurality of comparatively thick panes of glass are'disposed in the frame and lie against member I53 at their lower edges and against the depending flange of I5I at their upper ends. Pan-es I6 I are maintained in proper assem bled position by means of an angle bar I62, which is secured to member I5I by means of bolt and nut assemblies I63. The lower ends of panes I6I are restrained against outward movement by means of a retaining strip I64 which is secured to member I49 by means of screws I65.

Secured to the depending flange of member I49, by means of nut and bolt assemblies I66 and a clamping strip I61, are a plurality of short flaps I68 and I68a and a plurality of longer flaps I69 and I69a. Although flaps I68 and I69 may be disposed in alignment if desired, I preferably stagger them in order to reduce escapage of abrasive to a minimum. Pivot pins I extend through apertures i'lI located in end plates I52 and are adapted to be journaled in apertures 14 of member 69. A pair of nuts (not shown) are threaded on pins I16 and are preferably taken up sufficiently to provide adequate friction to hold the window assembly in any adjusted position. Washers I12, preferably constructed of nonmetallic material such as leather or fiber or the like, are preferably mounted on pivot pins I10 and serve to space the window structure from the frame structure. When the window is in place in the frame, portions I13 of the window are adapted to contact and be stopped by depending flange 61 of member 63.

Referring now to Figure 5, it is seen that nozzle I28 extends through flaps I68 and I69 and that flaps I 68 terminate near the path of travel of the nozzle, with the result that, when the carriage is moved horizontally, the nozzle sweeps aside substantially only a single set of flaps, with the result that resistance to movement of carriage is small. Flaps I680. and 5911, located at the extreme ends of the structure, are made wider for the reason that it has been found that their greater inherent tendency to remain flat prevents them from wedging themselves in between the guides and other moving parts of the construction.

The operation of my device is as follows. The stone or other work is placed within the room, switch I45 is operated to provide illumination for the work, and handle I I3 and nozzle I28 are grasped and manipulated in the manner previously described, to move the nozzle over the face of the work. While the work is progressing, the operator sights through windows I6I and visually follows the steps thereof. When it is desired to make a. closer inspection of the work or obtain a measurement or a physical inspection thereof, the lower edge of the window is pushed inwardly to thereby rock it in a counter-clockwise direction (Figure 12) away from stop flange 61. If desired the window may be rocked in this direction through an angle of 180 to obtain a small inspectionopening or the workman may rock it through an. angle of substantially 270 into the position illustrated in Figure 1 to obtain a full view of the work. As movement of the window in this manner lifts the flaps away from the nozzle, the inspection operation does not disturb the latter. Referring to Figure 1, it is seen that movement of the window into the position shown has brought the flaps on the top side thereof. In view of the fact that the window is pivoted oif center (Figure 12) it may readily clear flange 61 and be brought into this position.

In order to releasably maintain window C in the position shown in Figure 1, dog or latch member may be provided, but I preferably attain this result by tightening pivots I10 sufiiciently when assembling the machine so as to compress washers I12 and provide enough friction to hold the window in any desired adjusted position.

Although I have illustrated and prefer to employ a nozzle support that maintains the nozzle in a position that is normal to the face of the work, in order to prevent the worker from undercutting the stone or other material that is being handled by the apparatus, it is to be understood the nozzle may be held in other positions on the support, or in fact other types of nozzle supports may be mounted on carriage D without departing from the spirit of my invention.

As the curtain is moved Vertically, flaps 23 and 32 cooperate therewith to maintain a substantially tight seal to prevent the dust laden air contained in the room from getting into the atmosphere. As flap 32 is inclined, any sand or dust that may drop downwardly is deflected away from curtain 54 thereby. It is also observed that, ascurtain 54 is wound upon roller 52, sand or other foreign material cannot be carried thereon as the horizontal reach of curtain 54, formed by idler roller 5|, functions as a shelf or a baflle member. Moreover, as curtain 54 passes over idler roller 5|, any sand that may be adhering to the rear face of the curtain is removed therefrom as the comparatively small diameter of the idler roller causes the .pores of the material to open up during this operation.

'Although I have illustrated the sand bafiiing flaps as being secured to a window that is pivoted for work inspection movements, it is to be understood that the flap construction may function equally well with any other window whose lower edge is adapted to be lifted as it is opened, for instance, window C may be supported upon links or be mounted for vertical sliding movement in frame B, in either case the flaps would be lifted out of the way when the window is raised for inspection of the work. On the other hand, the window may be mounted for downward movement on frame B, and in such case the flaps would move downwardly behind curtain 54 when the window is opened, and the appended claims are intended to embrace my construction when the parts are related in this manner. Moreover, the panes or the screen may be omitted from the window and a. satisfactorily operating structure obtained, but I preferably employ the glass-screen combination as the glass panes positively prevent dust from passing through the window, and the screen protects the glass from flying chips of stone.

The sand baffling flaps have been shown as attached to the window and this is a highly desirable arrangement for the reason that when the window is opened the flaps are lifted clear and afford full vision of the work, but it is to be understood that, if desired, the flaps may be mounted on a separate movable frame which is actuated by window opening movements to lift the flaps out of the way and afford inspection of the work without departing from the spirit of my invention.

Although I have shown my window and baffle flap construction as associated with a vertically movable curtain, it is to be understood that it may be stationarily mounted in a room or like front when the work handled by the apparatus is of such dimensions that it does not require great vertical nozzle movements and the appended claims are intended to embrace my construction when it is used in this manner.

Referring now to- Figures 17 to 20, inclusive, I have illustrated a modified form of my invention and in order to clarify the disclosure, certain parts which are similar to those employed in the first form of my invention, such as the lamps, the nozzle, and the nozzle carriage, have been omitted. In this form of the invention, frame members IIa are interconnected by lower and upper members. I2a and I3a respectively. Mounted for vertical movement within the guides located on members IIa is a main frame structure I16. A window structure I1! is pivoted at H8 in the main frame, and connected to the lower end thereof are a plurality of flaps I682) which function in amanner similar to those employed in the first form of my invention.

A pair of cords I19 are connected to the main frame at lateral spaced points and extend upwardly over pulleys I8I, which are supported on the room and are connected to counterweights I82. Upper curtain I83 is connected to member I3a at its upper end and rests on the top of main frame I16. A lower curtain I84 is connected to the lower side of the main frame and extends downwardly and rests upon member In. Curtains I83 and I84 are preferably stiffened by means of rods I85 which are secured thereto by means of easements I86 which may be stitched or otherwise secured to the curtain. Curtains I83 and I84 preferably are guided in the same guides that accommodate frame I16, and it is observed that, as the frame moves upwardly, the upper curtain folds up in an accordion formation on the top of the frame, and the lower curtain is extended,'whereas, when the frame is lowered, the upper curtain is extended and the lower curtain folds up into an accordion formation on member I2a..

When it is desired to inspect thework. the

window I I! may be swung into the partially opened position shown in Figure 18, or it may be rocked through substantially 270 into the position shown in Figure 19, which gives the maximum opening.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a room front construction, upper and lower members disposed substantially in a vertical plane, said members being vertically spaced to provide a horizontally extending opening therebetween, a horizontally extending window disposed in said opening and mounted for rocking movement about a horizontal axis; an abrasive baffling curtain connected to said window and depending downwardly therefrom into a position immediately adjacent the rear face of lower member when said window is closed, said window being operable to lift and also move said curtain further to the rear of said lower member when said window is opened.

2. The construction described in claim 1, wherein said window is mounted for rocking movement through an angle greater than 180, whereby it may be rocked to bring said curtain onto the top side thereof.

3. The construction described in claim 1, wherein said window is automatically operable to restore the depending portion of said curtain to its position adjacent the rear face of said lower member when it is moved from open to closed position.

4. The construction described in claim 1, together with means for effecting synchronous vertical movement of said upper and lower mem bers and said window.

5. In a room front construction, an upper member and a lower member disposed substantially in a common vertical plane, said members being vertically spaced to provide a horizontally extending nozzle manipulating opening therebetween; a horizontally extending inspection window disposed in said opening and operable toclose the upper portion of said opening when it is closed, means for mounting said window for rocking movement about a substantially horizontal axis located intermediate the top and bottom edges of the window, whereby said window projects a minimum distance forwardly of the plane of said members when it is opened; and a flexible abrasive bafiling curtain secured to said window and adapted to depend therefrom.

6. The construction defined in claim 5, wherein said window is operable to rock through an angle of substantially 2'70", whereby the depending portion of said curtain may be brought up and supported thereby.

7. In a room front construction, an upper member and a lower member disposed substantially in a common vertical plane, said members being vertically spaced to provide a horizontally extending opening; a guide mechanism mounted adjacent the front face of the upper edge of said lower member; an abrasive blasting apparatus supported upon said guide mechanism for movement into various lateral positions; a window disposed in said opening and mounted for rocking movement about a horizontal axis; a flexible abrasive baffling curtain secured to said window and having a depending portion disposed adjacent the rear face of the upper edge of said lower member when said Window is closed, said window being operable to lift said curtain and move it rearwardly of said lower member and said abrasive blasting apparatus when it is moved into open position.

8. In an abrasive blasting device supporting mechanism, a horizontally disposed guide member comprising a U-shaped element having an outwardly directed flange on each leg thereof, said flanges being disposed in a common plane; and a carriage, equipped with rollers for engaging each of said flanges, mounted for horizontal movement on said guide element.

9. The mechanism described in claim 8, together with an elongated plate rigidly secured to said guide element and disposed substantially in the plane of said flanges.

10. In a room front construction, a pair of vertically spaced rollers having an apertured curtain rolled thereupon; a hollow counter-weight supporting member connected to the upper of said rollers; and a tension spring disposed within said supporting member and connected to the lower of said rollers.

11. In an abrasive blasting room front construction, a front structure, a frame mounted for vertical guided movement upon said structure, an extensible and contractible curtain secured to the top of said structure and sealingly associated with the top of said frame, said curtain being adapted to fold upon itself when said frame is moved upwardly in its guides together with means for causing said curtain to fold in definite lines when said frame is moved upwardly.

12. A window assembly for use with a room front construction, comprising a frame member, a transparent pane and a screen mounted in said frame member, said screen being disposed in sealing relation to said frame at its top edge and spaced therefrom at its lower edge, to thereby permit abrasive that passes through said screen to escape from between the latter and said window.

13. The construction described in claim 12, wherein the lower edge of said frame inclines downwardly away from said window and screen, for conducting abrasive away therefrom.

WM. A. ROSENBERGER. 

